1. Field of the Invention
The present invention relates to an engine-supporting structure for a motorcycle, in which a collar is interposed between an engine and an engine-supporting frame portion of a vehicle body frame, and to methods of using the described engine-supporting structure to support the engine on the vehicle body frame, in which a rod-shaped member is used to interconnect the engine-supporting frame portion, the collar, and the engine.
2. Description of the Background Art
In some motorcycles, a method of supporting the engine on an engine-supporting frame portion on a vehicle body frame is known, in which a rod-shaped member, such as a bolt, is inserted into the engine-supporting frame portion, and the engine is held in place by tightening a nut onto an end portion of the rod-shaped member.
In some cases, when the engine is mounted on the engine-supporting frame portion, a gap is created between the engine-supporting frame portion and the engine, and a collar is interposed between the engine-supporting frame portion and the engine, in order to bridge the gap.
However, in this previously known approach, the collar is simply pressed against the engine-supporting frame portion and the engine, on the respective end surfaces thereof, by a tightening force of the nut, and hence, the collar may eventually slip in relation to the engine or to the engine-supporting frame portion.
When the collar according to the known design slips, the end surfaces of the collar may be displaced from the normal abutment position on the engine or on the engine-supporting frame portion.
As a countermeasure for preventing displacement of the end surfaces of the collar from the engine or the engine-supporting frame portion, there is a known method in which the end surfaces of the collar are formed with integral projections and recesses thereon, for engaging with the engine or the engine-supporting frame portion (for example, see Japanese patent publication JP-UM-A-57-165827).
FIG. 24 of the present application is a reproduced version of FIG. 3 from Japanese patent publication JP-UM-A-57-165827, and is included herein for discussion purposes. FIG. 24 is a side plan view, partially cut away and partially in cross-section, showing some prior art engine mounting hardware. In FIG. 24 of the present application, the components of the drawing have been renumbered from the numbering used in the original.
FIG. 25 of the present application is taken along the line 25—25 in FIG. 24, showing an example in which the plurality of claws 301, formed on the cylindrical body 300, are engaged with the shackle body 305.
According to JP-UM-A-57-165827, a number of claw-like serrations 301 are formed at the end of a cylindrical body 300, and valleys 302 are formed between adjacent claws 301, 301. In use, the cylindrical body 300 is fitted onto a shaft 303, the claws 301 of the cylindrical body 300 are brought into abutment against a shackle body 305, and a nut 307 is tightened on a screw portion 306 at the extremity of the shaft 303.
By tightening the nut 307, the claws 301 on the cylindrical body 300 can be brought into engagement with the shackle body 305. In this manner, the cylindrical body 300 can be integrally connected to the shackle body 305, and the cylindrical body 300 can be prevented from slipping with respect to the shackle body 305.
According to this approach, since the claws 301 are formed at the end of the cylindrical body 300 like serrations, the claws 301 are formed continuously along the peripheral wall of the cylindrical body 300. When the plurality of claws 301 are provided continuously, this may lead to the following difficulties:
Provision of the plurality of claws 301 on the cylindrical body 300 results in continuous engagement between the plurality of claws 301 and the shackle body 305. Therefore, a plurality of continuous indentations 309 is formed by engagement of the plurality of claws 301 with the shackle body 305.
Therefore, for example, when the cylindrical body 300 is dismounted, for example, for maintenance, and the cylindrical body 300 is re-mounted after maintenance is complete, there is no portion for engaging the plurality of claws 301 again remaining on the shackle body 305.
Therefore, the plurality of claws 301 cannot be suitably engaged with the shackle body 305 when re-mounting the cylindrical body 300.
Therefore, when re-mounting the cylindrical body 300, it is necessary to replace the shackle body 305 with a new one or repair it by bridging the indentations 309 on the shackle body 305, and then forming a flat portion on the shackle body 305.
In addition, since the claws 301 are continuously formed serrations on the cylindrical body 300, extremities of the claws 301 are pointed as shown in FIG. 25. Therefore, when allowing the claws 301 to engage with the shackle body 305, the extremities of the claws 301 tend to break easily.
Therefore, it is difficult to bring the claws 301 into suitable engagement with the shackle body 305 when re-mounting the cylindrical body 300.
Although the known inventions have some utility for their intended purposes, there is still a need to provide an improved engine-supporting structure for a vehicle. More particularly, there is a need for an improved engine-supporting structure for a vehicle which simplifies engine maintenance accessibility, and which facilitates re-mounting of a cylindrical body between an engine casing and an engine-supporting frame member.